Holographic method and materials to detect and prevent forgery in identity cards

Abstract

Security and identity cards including at least one hologram of the card, or part of the card, are disclosed. Holographic methods and materials to detect and prevent forgery in identity cards such as credit cards and access cards to security areas are disclosed. This invention employs microholograms that are recorded in very small areas on the card and that are not readily visible to the bearer. Special recording materials for high efficiency holograms are used to allow the confinement of the recording in an about 10 to about 100 micron size area. Apparatus for the recording and reading of the holograms are also disclosed.

Claims

1. An identity card comprising:

a card; and

one microhologram or a multiplicity of microholograms recorded on a high efficiency variable index material depicting the card wherein said microhologram or microholograms are located within micro-size holes on one surface or a multiplicity of surfaces of the card.

2. The identity card of claim 1 wherein the card is plastic, metal, paper, cardboard, laminated or a metal alloy.

3. The identity card of claim 1 wherein the variable index material is an organic semiconductor.

4. The identity card of claim 1 wherein 2,3, or 4 holograhic images are comprised within the card.

5. The identity card of claim 1 wherein the microhologram has a thickness of from about 20 to about 100 microns and a diameter of from about 10 to about 100 microns.

6. The identity card of claim 1 wherein the surface of the card includes a design incorporating the microhologram.

7. The identity card of claim 1 wherein the identity card is a social security card, a drivers license, or an employee access card.

8. The identity card of claim 1 wherein the micro-size holes are about 10 microns diameter.

9. The identity card of claim 1 wherein the micro-size holes are between about 40 and about 60 microns diameter.

10. The identity card of claim 1 wherein the micro-size holes have a depth of about 500 to about 1000 microns.

11. The identity card of claim 1 wherein the high efficiency variable index material comprises an organic semiconductor.

12. The identity card of claim 11 wherein the organic semiconductor is a polyvinylcinnamate.

13. The identity card of claim 1 wherein the high efficiency variable index material comprises poly-2,5-thienylenevinylene, 2,5-methoxy-p-phenylenevinylene, a polymer of vinyl naphthalene, a polymer of vinyl-2-fluorene, a polymer of vinyl-3-polydiphenyl-3-propene or vinyl-polyvinyl-2-fluorene.

14. The identity card of claim 1 wherein the high efficiency variable index material comprises a photopolymerizable, photoisomerizable or photodegradable material.

15. The identity card of claim 14 wherein the photodegradable material is polymethyl methacrylate, vinylidene fluoride/hexafluoropropylene copolymer or polyhexafluoropropylene.